Label applicator

ABSTRACT

A label applicator having an operating cycle including a labelapplying head, a heater carried by the head for heating the head, and current supplying and regulating circuit means for energizing the heater and for controlling the temperature of the head including variable resistance means and switch means for automatically bypassing the resistance means during a portion of the operating cycle.

Unite Etates ateitt [56] References Cited UNITED STATES PATENTS [72] Inventor Dennis W. Clem Toledo, Ohio 793,980

2,692,063 10/1954 Ketchpel............,......... 3,097,284 7/1963 TreadwelL.

3,106,630 10/1963 Klamp.......... 3,196,962 7/1965 Allen et al.

Primary Examiner- [21 Appl No.

[22] Filed Jan. 27, 1969 [45] Patented Oct. 26, 1971 [73] Assignee The Reliance Electric and Engineering Company Toledo, Ohio Benjamin A. Borchelt Assistant Examiner-D. A. Bent [54] LABEL APPLICATOR 8 Claims, 5 Drawing Figs.

perature of the head including variable resistance means and [50] Field of 156/304, switch means for automatically bypassing the resistance means during a portion of the operating cycle.

PATENTEDnm 26 I871 3, 15,051

sum 1 OF 4 INVENTOR. DENNIS W. CLEM ATTORNEY PATENTEDum 26 I9?! SHEET 2 BF 4 INVENTUR. DENNIS W. CLEM ATTORNEY PATENTEUUBT 26 1am SHEET 0F 4 INVENTOR. DENNIS W. CLEM ATTORNEY LABEL APPLICATOR BACKGROUND OF THE INVENTION 1. Field of the Invention The invention relates to the packaging art, and particularly to temperature control of the label-applying heads in automatic label applicators.

2. Description of the Prior Art The thennostat controls in prior label applicators, such as disclosed in U.S. Pat. No. 3,284,265issued Nov. 8, 1966 in the names of F. C. Carroll and F. H. Weihs, must be set so high to attain satisfactory results during a long run of package labeling that, when the label applicators are at rest with their heaters on, the temperatures of the label-applying heads rise to much higher temperatures than are required.

SUMMARY OF THE INVENTION A rheostat control is used for controlling the temperature of the label-applying head. When the machine is stopped with the heater for the head on but with the vacuum pump for sucking air through the head off, relatively low current is supplied to the heater. When the machine is running but no labels are being delivered, the head rotates back and forth and the vacuum pump is on, and a switch is closed to bypass the rheostat to supply higher current to the heater. Also when the machine is running and labels are being delivered, a second switch is closed to bypass the rheostat and supply higher current to the heater.

The objects of the invention are to improve techniques in labeling packages, to improve label applicators, and to improve temperature control in label applicators.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the label applicator;

FIG. 2 is enlarged side elevational view of the upper end of the label applicator shown in FIG. 1;

FIG. 3 is an enlarged vertical section view taken long the line 3-3 of FIG. 1;

FIG. 4 is a schematic wiring diagram of a current supplying and regulating circuit for energizing the label applicators heater and for controlling the temperature of the applicators label-applying head; and

FIG. 5 is a fragmentary, enlarged side elevational view of the middle part of the label applicator as viewed in FIG. 1.

A label applicator as contemplated in this invention is shown in FIG. 1 in its home position prior to the initiation of an automatic operating cycle. Labels are delivered in the direction indicated by the straight arrow in FIG. 1 from a gravity chute (not shown) of a printer as illustrated in the above U.S. Pat. No. 3,284,265. The printer is used in connection with an automatic computing weighing scale which together weigh commodities and issue printed tickets or labels each bearing the net weight, price per pound, and computed value of a weighed commodity together with such variable data as the date, store code, commodity name, and commodity grade. The printer delivers the labels selectively in a faceup or a facedown position. In automated operation, transfer mechanism, such as shown in U.S. Pat. Nos. 3,194,710 and 3,264,161 issued July 13, 1965 and Aug. 2, 1966, respectively, to W. F. Stremke, Jr. et al. and to W. F. Stremke, Jr., respectively, and in U.S. Pat. Nos. 3,232,804 and 3,232,815 both issued Feb. 1, 1966 to K. L. Klopfenstein et al., move wrapped packages to and off the weighing scale and to from the label applicator.

The label applicator includes an upright casting fixed to two horizontal frame members 11 and comprising a sleeve 12 which journals a slidable tube 13. A shaft 14 is rotatably mounted atop the casting 10 and it carries a lever 15 which is urged clockwise as viewed in FIG. 1 about the axis of the shaft by a return spring 16 extending between a stationary pin 17 on the casting l0 and a pin 18 carried by the lever 15. A lever stop extending from the frame by engagement with a set screw 19 carried by the lever 15 limits clockwise rotation of the lever. A label chute 21 is fixed to the shaft 14 and is held in its position shown in FIG. 1 by the return spring 16.

The lower end of the slidable tube 13 is bifurcated for the reception of an interlock stop plunger 22 (FIG. 5). A stop surface 23 of the bifurcation engages the plunger 22 when it is in its extended position as shown in FIG. 5. A pin 24 through the lower end of the tube 13 pivotally connects two straps 25 one on either side of the tube. Each of the straps 25 is provided with an elongated slot 26. As arm 27 has one end between the straps 25 and is guided along the slots 26 by a pin 28 extending from either side of the arm27. Collars 29 on the pin 28 slide along the outer surfaces of the straps 25 and engage shock-absorbing rubber elements 30 carried on the straps when in the position shown in FIG. I. The other end of the arm 27 is fixed to a sleeve 31 which is rotatably mounted on a stationary shaft 32 and to which is fixed an arm 33. A spring 34 extending between a stationary element 35 and the arm 33 keeps a cam follower 36 engaged with a cam 37. The cam follower 36 is mounted to rock on a stationary shaft 38 and is connected to the arm 33 through linkage 39 which is pivoted at 40 to the cam follower 36 and is pivoted at 41 to the arm 33. The cam 37 is fixed to a rotatable power shaft 42. As shown in FIG. 1, the cam 37 holds the arm 27 up against the rubber shock absorbers 30 in opposition to a spring 43. During operation, the spring 43 pulls the slidable tube 13 down, the spring 43 extending between a stationary member 44 and the pin 24. To reach the pin 24, the spring 43 enters the lower open end of the tube 13 and is connected to the pin 24 inside the tube.

The upright casting 10 supports a stationary cam 45 having a foot 46 attached to the casting and hook-shaped upper end 47. The cam 45 has a curved cam surface 48 and a vertical, rectilinear cam surface 49.

The upper end of the slidable tube 13 carries a label head support 50 which journals two shafts 51 and 52. Shaft 51 carries a sprocket 53, held on the shaft by a collar 54, and a labelapplying head 55. Shaft 52 carries a sprocket 56 operatively connected to the sprocket 53 by means of a chain 57. The sprocket drive ratio is 1:2, i.e., one revolution of sprocket 56 causes two revolutions of sprocket 53. A cam-following roller 58 is rotatably mounted between the bifurcations of a lever 59 fixed to the shaft 52. The roller 58 follows cam surfaces 48 and 49. A rubber bumper 60 is engaged by the bottom of the head 55 when the head is in its home position shown in FIG. 1. One rotation of the cam 37 permits the spring 43 to pull the slidable tube 13 down and then the arm 27 lifts the slidable tube upwardly. Downward motion of the tube 13 drives the cam-following roller 58 around the curved cam surface 48 causing simultaneous rotary and rectilinear downward motion of the label-applying head 55 until a stop pin 61 carried by the collar 54 engages a stop pin 62 carried by the support 50. At this point, the head 55 is horizontal, rotary motion taking place quite rapidly because of the 1:2 sprocket ratio. The camfollowing roller 58 then follows the straight cam surface 49 downwardly until the head 55 reaches a random package height position.

The label-applying head 55 includes a hot plate 63 which is located between the wings of the label chute 21. A label sliding down the chute 21 and onto the hot plate 63 is stopped by a pin 65 which is urged upwardly by means of a spring 66 that is received in an opening in the head 55. The hot plate 63 is provided with perforations 67 communicating with a vacuum pump 68 and an electrical heater (heater resistor 69 shown in FIG. 4) to supply the requisite heat for activating the thermoactivatable adhesive coatings on the labels. During each operating cycle, a cam 70 on the drive shaft 42 drives a post 71 downwardly in opposition to a spring 72 causing the pump 68 to suck air through the perforations 67 during downward motion of the head 55 in the absence of a label on the head or to create a vacuum holding a label on the head. The return spring 72 causes the vacuum to be released through the perforations 67 during upward motion of the head 55. It is not necessary that release of the vacuum occur immediately after application of a label because of the action of the adhesive sticking to a package is enough to cause separation of such label from the head 55. The pump 68 is connected to the head 55 by means of plastic hose 73 which runs from the pump to a T-fitting 74 and then up and out of the top of the slidable tube 13 to communicate with the head 55. Additional plastic hose 73 extends from the T-fitting 74 to connect the pump 68 to a label interlock 75. The three ends of the hose 73 are held in the T-fitting 74 by cement and electrical wires are inside the hose 73 running from the T-fitting 74 to energize the heater (resistor 69).

The label interlock 75 is attached to a bracket 77 carried by the stationary sleeve 12 and includes a cylinder 78, a rubber diaphragm 79, held on the cylinder by means of a spacer 80 and a cap 81, and the plunger 22 which is slidable in a bearing 82. The plunger 22 extends through a diaphragm and is fixed in a sleeve 83. A pin 84 also is fixed in the sleeve 83 to be movable as one with the plunger 22. The plunger 22 is held in its extended position as shown in FIG. 1 by a spring 85 which is compressed between shoulders 90 of the cylinder and shoulders 91 of the sleeve 83. In operation, no label on the head 55 permits air to be sucked through the perforations 67 in the hot plate 63 and no vacuum is built up in the cylinder 78. The plunger 22 then is held in its extended position by the spring 85. However, a label on the head 55 covers the perforations 67 in the hot plate 63 and a vacuum builds up in the cylinder 78, whereupon the diaphragm 79 moves the plunger 22 and the pin 84! to the left as viewed in FIG. ii. The stop surface 23 of the bifurcated lower end of the slidable tube 13 engages the plunger 22 when it is in its extended position. Movement of the pin 84 to the left closes a normally open switch 86 (FIGS. 1, 4 and One operating cycle (one revolution of the drive shaft 42) causes the end of the arm 27 to move downward from its position shown in FIG. 1 to a point near the bottom of the slots 26 and then back. We label is on the head 55, the slidable shaft 13 follows under the action of the spring 43 until the head 55 comes to rest on a package (random package height); however, the arm 27 continues downwardly and then during its upward motion engages the shock absorbers 30 and lifts the head 55 in opposition to the spring 43 back to its home position,. The label on the head by creating suction in the cylinder 78 causes the plunger 22 to be moved out of the path of the stop surface 23 on the slidable tube 13. If there is no label on the head, the slidable tube 13 is permitted to move downwardly only until the stop surface 23 on the slidable tube 13 engages the plunger 22 to prevent the hot head 55 from descending without a label and burning a package.

A cam 87 on the drive shaft 42 closes a switch 88 about lOO degrees per revolution of the shaft 42. The high part of the cam 37 holds the head up during a dwell period. As the roller 89 on the cam follower 36 moves onto the low part of he cam 37, the head 55 simultaneously rotates forward and moves downwardly. The head 55 continues to move downwardly until it is stopped by the interlock plunger 22 or by a package or until the roller 89 reaches the bottom of the low part of the cam 37 and then is moved upwardly as the roller 89 approaches the high part of the cam 37. Just before the roller 89 reaches the high part of the cam 37, the head simultaneously rotates back and moves upwardly to its home position.

Hand-labeling is accomplished by picking up a package and resting it against the label chute 21 which pivots counterclockwise about the axis of the shaft 14 in opposition to the return spring 16 until the chute engages a stop 92 extending from the head 55. The package depresses the label stop pin 65 in opposition to the return spring 66 and the heat-activated label sticks to the package.

Automatic labeling is accomplished by moving a wrapped package to a suitable position below the label-applying head 55 and turning the drive shaft 42 one revolution (one operating cycle). In the absence ofa label on the head 55, the arm 27 moves down toward the bottoms of the strap slots 26 and then back to its home position. The head 55, however, driven by the spring 43 moves downwardly only until the stop surface 23 engages the plunger 22. This prevents the head 55 without a label from descending and burning a package. In the presence of a label on the head 55, the head 55 moves down until it engages the package and the label sticks thereto. The package depresses the label stop pin 65 in opposition to the return spring 66.

The circuit shown in FIG. 4 supplies and regulates current for the heater resistance 69 of a heater cartridge (FIG. 3). A rheostat or variable resistance 93 when the switches 86 and 83 are open reduces the line voltage to the heater resistance 69 in accordance with the rheostat setting. A fixed resistor 94 in series with the rheostat 93 is used to minimize the wattage consumed by the rheostat 93 to prolong its life. With both switches 86 and 88 open and using a l lS-volt source, 60 to 99 volts as an example may be supplied to the heater resistance.

When the machine is stopped with the heater for the labelapplying head 55 on but with the vacuum pump 68 for sucking air through the head off (off because cam 70 is not rotating), relatively low current is supplied to the heater because the switches 86 and 88 are open. Using a ll5-volt source, a fixed resistor 94 having a value of 50 ohms, a rheostat 93 having a value from 0 to 175 ohms, and a heater resistance 69 having a value of 170 ohms, the face temperature of the hot plate 63 varies from about 255 to abut 480F. depending on the rheostat setting. Satisfactory results cannot be obtained through the use of the rheostat 93 alone without the switches 86 and 88. Using the rheostat 93 alone requires a high setting of the rheostat to make the labels stick satisfactorily during a long run of package labeling. Such high setting when the label-applying head is at rest produces a much higher temperature than is required. Usually when the machine is stopped with the heater for the head on and the vacuum pump 68 for the head off, the rheostat is set to regulate the temperature at about 300 to 350 F.

When the machine is running but no labels are being delivered to the label chute 21, the head rotates forward and moves down until the stop surface 23 engages the plunger 22 and rotates back and moves up into its home position. etc. Also, the vacuum pump is on sucking air through the head. The overall coefficient of conductance increases and there is an increased rate of heat loss. In order to maintain a substantially constant head temperature, the cam 87 closes the switch 88 during a portion of every operating cycle. As an example, this portion is degrees per revolution of the shaft 42. Closed switch 88 bypasses the fixed resistor 94! and the rheostat 93 placing full line voltage on the heater resistance 69 during the closed period of the switch. Thus, more current is supplied to the heater when the machine is running than when the machine is stopped. The cam 87 is tailored to produce a substantially constant head temperature.

When the machine is running and labels are being delivered, the switch 86 also is closed to bypass the fixed resistor 94 and the rheostat 93 and supply higher current to the heater. There is no overlap of the times when the switches 86 and 88 are closed. The head 55 rotates forward and moves down into engagement with the package and moves up and rotates back into its home position. This causes an even larger coefiicient of conductance. The switch 86 is closed by the pin 84 after the vacuum-operated interlock 75 senses that there is a label on the head and/or the stop surface 23 of the tube 13 is below the plunger 22. When the stop surface 23 of the tube 13 is below the plunger 22, the outside of the tube 13 prevents return of the plunger 22 to its tube-obstructing position. Delivery of the label to the package releases the vacuum because air then is sucked through the face perforations 67. However, the end of the plunger 22 then rests on the outer side of the tube 13 until the stop surface 23 moves above the plunger 22.

The switch 86 is closed by the pin 84 somewhere during the time that the stop surface 23 of the tube 13 is moving down toward the plunger 22 (it takes time to evacuate the system and build up the vacuum). Once the stop surface 23 of the tube 13 is below the plunger 22, the outside of the tube 13 prevents return of the plunger 22 to its tube-obstructing position during about 38 degrees per revolution of the shaft 42 while the tube 13 moves downwardly and during about another 38 degrees while the tube 13 moves upwardly. This adds up to closing the switch 86 during about 80 degrees per revolution of the shaft 42. The cam 87 positioned to close the switch 88 immediately after the switch 86 opens. Hence, switches 86 and 88 function as one switch when labels are being delivered, i.e., the switch 86 is closed for about 80 degrees and as soon as its opens the switch 88 is closed for about 100 degrees so that, when the machine is running and labels are being delivered, the fixed resistor 94 and the rheostat 93 are bypassed much longer than they are when the machine is running but no labels are being delivered to the label chute 21. Closing of the two switches produces a substantially constant head temperature.

The switch means automatically bypasses the heater resistance 69 during a portion of each operating cycle and includes the switch 88 and means for operating the switch 88 independently of the presence or absence ofa label on the head in position for use and the switch 86 and means for operating the switch 86 in the presence ofa label on the head in position for use. The means for operating the switches operate them without substantial overlap.

It is to be understood that the above description is illustrative of this invention and that various modifications thereof can be utilized without departing from its spirit and scope.

Having described the invention, I claim:

1. An automatically operable label applicator comprising, in combination, a movably mounted head, a heater carried by the head for heating the head, means for regulating current supplied to the heater, and drive means for moving the head and operating the current-regulating means according to whether or not the head is moving.

2. A label applicator according to claim 1 wherein the head defines perforations, pump means provides suction through the perforations, and means are provided for detaching said suction and operating the current-regulating means to supply additional current to the heater in the absence of said suction 3. A label applicator according to claim 1 wherein the current-regulating means includes variable resistance means and switch means for bypassing the resistance means and operated by said drive means during at least a portion of the time when the head is moving, whereby relatively low current is supplied to the heater when the head is at rest.

4. A label applicator comprising, in combination, a movably mounted head, a heater carried by the head for heating the head, drive means for moving the head, and current supplying and regulating circuit means for energizing the heater and for controlling the temperature of the head including variable resistance means and switch means, operated by the drive means, for automatically bypassing the resistance means during at least a portion of the time when the head is moving, wherein the head defines perforations, pump means provides suction through the perforations, detection means are provided for detecting said suction, and interlock means, operated by said detection means, are provided which prevent movement of the head beyond limits in the presence of said suction.

5. A label applicator having an operating cycle comprising, in combination, a movably mounted head, a heater carried by the head for heating the head, drive means for moving the head, and current supplying and regulating circuit means for energizing the heater and for controlling the temperature of the head including variable resistance means and switch means, operated by the drive means, for automatically bypassing the resistance means during a portion of the operating cycle.

6. A label applicator according to claim 5 wherein the head defines perforations, pump means provides suction through the perforations, detection means are provided for detecting said suction, and the switch means includes a first switch which is operated by the drive means during said portion of the operating cycle independently of the presence or absence of said suction.

7. A label applicator according to claim 6 wherein the switch means also includes a second switch operated by said detection means in the absence of said suction.

8. A label applicator according to claim 7 wherein the drive and detection means operate the first and second switches, respectively, without substantial overlap.

( 90-1050 UNITED STATES PA'IENT OFFICE CIIHTIFICATE OF CORREC l ION Patent No. 3,616,051 Dated October 26, 1971 Inventor(s) Dennis W. Clem It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 9, "As" should read --An-.

Column 5, line 36, "detaching" should read --detecting-.

Signed and sealed this 18th day of April 1972.

(SEAL) Attest:

EDWARD M.FLETCHER ,JR ROBERT GOTTSCHALK Atte sting Officer Commissioner of Patents 

2. A label applicator according to claim 1 wherein the head defines perforations, pump means provides suction through the perforations, and means are provided for detaching said suction and operating the current-regulating means to supply additional current to the heater in the absence of said suction
 3. A label applicator according to claim 1 wherein the current-regulating means includes variable resistance means and switch means for bypassing the resistance means and operated by said drive means during at least a portion of the time when the head is moving, whereby relatively low current is supplied to the heater when the head is at rest.
 4. A label applicator comprising, in combination, a movably mounted head, a heater carried by the head for heating the head, drive means for moving the head, and current supplying and regulating circuit means for energizing the heater and for controlling the temperature of the head including variable resistance means and switch means, operated by the drive means, for automatically bypassing the resistance means during at least a portion of the time when the head is moving, wherein the head defines perforations, pump means provides suction through the perforations, detection means are provided for detecting said suction, and interlock means, operated by said detection means, are provided which prevent movement of the head beyond limits in the presence of said suction.
 5. A label applicator having an operating cycle comprising, in combination, a movably mounted head, a heater carried by the head for heating the head, drive means for moving the head, and current supplying and regulating circuit means for energizing the heater and for controlling the temperature of the head including variable resistance means and switch means, operated by the drive means, for automatically bypassing the resistance means during a portion of the operating cycle.
 6. A label applicator according to claim 5 wherein the head defines perforations, pump means provides suction through the perforations, detection means are provided for detecting said suction, and the switch means includes a first switch which is operated by the drive means during said portion of the operating cycle independently of the presence or absence of said suction.
 7. A label applicator according to claim 6 wherein the switch means also includes a second switch operated by said detection means in the absence of said suction.
 8. A label applicator according to claim 7 wherein the drive and detection means operate the first and second switches, respectively, without substantial overlap. 